Homemade Cream of Mushroom Soup

One news item in 2018, while sad, was a little different from much of the usual fare. In October, Dorcas Reilly, the woman who invented the green bean casserole, passed away at the age of 92. She worked for Campbell’s (the soup people) and developed other famous recipes: tuna noodle casserole, tomato soup meatloaf, “souperburgers”, and others.

Green Bean Casserole, like many casseroles of the 50s and 60s, has some of its appeal in its ease and simplicity. You simply stir together one can of Campbell’s cream of mushroom soup, milk, soy sauce, green beans, and salt and pepper, top with French’s Crispy Fried Onions and bake.

But what is in that cream of mushroom soup? I don’t know what was in it when Ms. Reilly developed the recipe but now it contains: Water, Mushrooms, Vegetable Oil (Corn, Canola, And/or Soybean), Modified Food Starch, Wheat Flour, Contains Less Than 2% Of: Salt, Cream (Milk), Whey*, Soy Protein Concentrate, Monosodium Glutamate, Yeast Extract, Flavoring, Garlic*. *dehydrated. (from Campbell’s website) If you opt for the lower sodium variety, it may contain cottonseed oil and has a higher sugar and lower protein content.

I don’t know about you, but most of those are things I don’t want in my soup. Even though once a year on Thanksgiving probably won’t hurt you, why not learn to make a classic mushroom soup? Serve it as soup one night, then use it another for the comfort food green bean casserole you’re craving. Your taste buds and body will thank you!

This recipe has a few similarities to the Campbell’s recipe, but only that it contains mushrooms, flour, and cream. Button mushrooms are replaced with oyster mushrooms (optionally others) and the milk is from grass-fed cows. An onion and some fresh thyme leaves amp up the flavor.

Since I cannot use wheat flour I looked for other ways to thicken my soup. My current favorite way is to use a combination of puréed cauliflower, turnip, and white sweet potato. The potato is, unsurprisingly, sweet, while the turnip has a bite, so I often use small amounts of each of these. The cauliflower is pretty neutral and I use mostly that in a mixture. For this batch of soup I only had a small turnip, but the mushrooms and cream are sweet enough that the flavor balanced out well. I also reduced my stock to 3 cups and added another cup of combined milk and cream (I skimmed this off my milk share so it was probably equivalent to half and half). Decadent, yes, but not too rich.

If you can tolerate wheat/gluten, then the classic roux is an excellent way to thicken a soup. Using sherry to scrape up the yummy brown bits from the bottom of the pot is also a classic cooking method and one worth doing. If you are not a sherry drinker, substitute white wine, vermouth, or brandy for the sherry. If you want a non-alcoholic option use cider or white wine vinegar diluted by half (water or broth).

Another option to try is substituting half shiitake mushrooms for the oyster mushrooms. This option was recommended by John Lawton of Possum Bottom Farms (who gave me the recipe) and the one I chose. I weighed half a pound of oysters, measured their volume, and then used the same amount, by volume, of shiitakes. Possum Bottom has shiitakes year-round now, and the current wet, cool weather has made log-grown mushrooms abundant from other vendors at market as well.

This recipe, as you may guess by quantity of mushrooms and liquids, makes a generous amount of soup. We had enough for supper, leftovers, and to make a green bean casserole. Not completely unlike the original recipe we used frozen French-cut beans, added our cream of mushroom soup (diluted with milk) where it looked about right in the casserole dish, and topped with roasted onions. Local, except for the green beans, and we’ll be sure to plan ahead next year and put some away. Bake until it seems about the right consistency for you and enjoy.

In a large heavy bottomed pot or Dutch oven, melt butter until foaming subsides. Add onion and cook until soft but not browned, about 5-8 minutes. Add mushrooms and ½ teaspoon each kosher salt and black pepper. Cook over medium heat, stirring often, until mushrooms have released their liquid and are soft, about 10 minutes.

Add flour and stir to coat the mushroom mixture. Cook for 1 minute. Add sherry and cook for an additional minute, scraping any brown bits from the bottom of the pot.

Stir in the chicken or vegetable broth and thyme leaves. Bring to a boil, stirring. (The soup may look, for the lack of a better term, “gloppy” at this point. This is normal! As you stir and the liquid heats, the roux will dissolve.)

Reduce heat to maintain a simmer and cook for 20 minutes, stirring occasionally. Remove from heat.

Transfer 1 ½ cups of soup to a blender or food processor and purée until smooth. Stir pureed soup back into the pot.

Stir in heavy cream and season to taste with salt and pepper.

Options:

Thicken without using a roux. Replace 1 cup of broth with cream or half and half. Also stir in a purée of a white or yellow vegetable: sweet potato, cauliflower, yellow carrot, turnip, or a mix of more than one.

Use half shiitake mushrooms. I replaced by volume rather than weight. Or use other mushrooms as available.

Replace sherry with white wine, vermouth, or brandy. Or replace with cider or white vinegar, diluted by half with water or broth.

Dilute soup with milk and use in green bean casserole.

Top with more thyme leaves and/or other chopped herbs, for color and flavor.